export function asDataUrl(value: any) {
    if (typeof value !== 'string') {
        return null;
    }
    return /^data:image\//.test(value) ? value : null;
}

export function toStr(value: any) {
    if (value === undefined || value === null) {
        return '';
    }
    return String(value);
}

export function readPositiveNumber(value: any, fallback: number) {
    const parsed = Number(value);
    if (!Number.isFinite(parsed) || parsed <= 0) {
        return fallback;
    }
    return parsed;
}

export function normalizeColor(value: any, fallback: string) {
    const normalized = firstValue(value);
    if (!normalized) {
        return fallback;
    }
    if (/^#[0-9a-fA-F]{6}$/.test(normalized) || /^#[0-9a-fA-F]{3}$/.test(normalized)) {
        return normalized;
    }
    return fallback;
}

export function firstValue(...values: any[]) {
    for (const value of values) {
        if (value === undefined || value === null) {
            continue;
        }
        const normalized = String(value).trim();
        if (normalized) {
            return normalized;
        }
    }
    return '';
}